Acrylate-styrene-acrylonitrile (ASA) resins have excellent weatherability and thus are widely used in building materials, exterior part materials for vehicles, and the like. However, the ASA resins can have poor impact resistance. To improve impact resistance, ASA resins are often used in the form of a composition including a rubber polymer. In such a case, the ASA resin compositions require a large amount of the rubber polymer in order to be applicable for uses requiring a high level of impact strength. Such a large amount of the rubber polymer, however, may result in poor heat resistance, which can limit their use in applications requiring a high level of heat resistance such as exterior part materials for vehicles.
In an attempt to provide an alternative, a method of enhancing heat resistance and impact resistance by alloying the ASA resin with a polycarbonate (PC) resin that has excellent heat resistance has been proposed. The PC/ASA resin is often used for a radiator grill for vehicles. However, unlike the PC resin having a high refractive index, the ASA resin has a relatively low level of refractive index. Thus, when the ASA resin is combined with the PC resin, the resulting resin composition may provide a molded product having poor coloring properties, which can limit its use in various products.